Topband: 1/4 wave sloper array info

[deuhs at earthlink.net]

Hello,

I'm putting up a 70 foot tower this summer for the 'high bands' and would like to put up a sloper
system to compliment my vertical (either 1/2 dipole or 1/4 wave wire) for 40, 80 or 160.  

Anyone have any article or first hand resources? 

I know of seen such plans in the past but can't quite find them, I think you can muster some gain out of 4 antennas.

Thanks,

Greg 
K0PJ/9